Over recent decades, developments in data communications technologies have continued to provide enhanced multimedia services (e.g., voice, data, video, etc.) to end-users. Such communications technologies encompass various delivery platforms, including terrestrial wire-line, fiber and wireless communications and networking technologies, and satellite communications and networking technologies. Further, in recent years, the proliferation of mobile communications has spurred an exponential growth in the provision of such enhanced multimedia services over mobile communications networks (both terrestrial and satellite based). As part of the continued evolution of such communications platforms and supporting technologies, the Digital Video Broadcasting (DVB) organization was formed (as an industry-led, global consortium of broadcasters, manufacturers, network operators, software developers, regulatory bodies and others) to advance the design of open interoperable standards for the global delivery of digital media and broadcast services.
As part of the standardization process for digital media and broadcast services, the DVB organization managed the adoption and publication of the DVB-S2 standard via recognized standards setting organizations (e.g., ETSI and TIA). DVB-S2 is a digital satellite transmission system standard covering framing structure, channel coding and modulation systems, designed for broadcast services (for standard and high definition television), interactive services (e.g., Internet access for consumer applications), and other broadband satellite applications. DVB-S2 represents a flexible standard, covering a variety of data and multimedia services delivered over satellite communications systems. The DVB-S2 standard covers various technological features, such as a flexible input stream adapter (suitable for operation with single and multiple input streams of various formats), a robust forward error correction coding (FEC) system based on low-density parity check (LDPC) codes concatenated with Bose Chaudhuri Hocquenghem (BCH) codes, a wide range of code rates (from ¼ up to 9/10), four signal constellations (ranging in spectrum efficiency from 2 bit/s/Hz to 5 bit/s/Hz), and adaptive coding and modulation (ACM) functionality (optimizing channel coding and modulation on a frame-by-frame basis).
Since its inception, the DVB-S2 standard has been adopted globally as a predominant standard for broadcast, interactive and other broadband applications and services over satellite communications networks. Currently, there are applications and services for terminals, particularly in the field of mobile communications, that require operation at lower signal-to-noise ratios (ES/N0). The current modulation and coding schemes (e.g., the modulation and coding schemes of the DVB-S2 standard), however, are unable to support the operational requirements for such current mobile and other low signal-to-noise ratio (SNR) terminals (e.g., below −3 dB). Further, such current modulation and coding schemes are unable to support the operational requirements for higher end terminals (e.g., above 15.5 dB). Additionally, the modulation and coding schemes of the current DVB-S2 standard lack sufficient granularity to meet the requirements of terminals in the growing field of broadcast, interactive and other broadband applications and services over satellite communications networks.
Further, in order for systems to provide for expanded sets of modulation and coding schemes, the associated signaling provided to the receiver for proper decoding (e.g., the physical layer header signaling) must similarly be expanded to support identification of the expanded modulation and coding. One method for expanding the physical layer header signaling to support expanded modulation and coding scheme sets would simply be to increase the header size to directly support the expanded header signaling. Bandwidth resources and system efficiencies, however, are already being pushed to the limits in support of new wideband systems and higher data rate applications. The addition of additional signaling bits in the physical layer headers would thus create the undesirable effect of utilizing already scarce bandwidth for additional signaling overhead. An alternative method has been proposed in technical literature, whereby two different scramblers could be employed to provide the signaling of an additional bit. Essentially, one scrambler would be used to signify an additional bit (e.g., the most significant bit) as being zero (0), and the other scrambler would be used to signify the bit as being one (1). This approach, however, suffers from disadvantages associated with cross-correlation of the two scramblers, which could never be zero, and thus, there will be more degradation from the original Reed-Muller code in performance.
What is needed, therefore, is an improved coding approach for providing efficient header signaling in broadband satellite communications networks, to provide support of expanded modulation and coding scheme sets that facilitate an expansion of the operational ranges of user terminals within such networks and finer granularity within such operational ranges.